net/sched/act_api.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/act_api.c  Packet action API.
   4  *
   5  * Author:      Jamal Hadi Salim
   6  */
   7
   8 #include <linux/types.h>
   9 #include <linux/kernel.h>
  10 #include <linux/string.h>
  11 #include <linux/errno.h>
  12 #include <linux/slab.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/init.h>
  15 #include <linux/kmod.h>
  16 #include <linux/err.h>
  17 #include <linux/module.h>
  18 #include <net/net_namespace.h>
  19 #include <net/sock.h>
  20 #include <net/sch_generic.h>
  21 #include <net/pkt_cls.h>
  22 #include <net/act_api.h>
  23 #include <net/netlink.h>
  24
  25 static void tcf_action_goto_chain_exec(const struct tc_action *a,
  26                                        struct tcf_result *res)
  27 {
  28         const struct tcf_chain *chain = rcu_dereference_bh(a->goto_chain);
  29
  30         res->goto_tp = rcu_dereference_bh(chain->filter_chain);
  31 }
  32
  33 static void tcf_free_cookie_rcu(struct rcu_head *p)
  34 {
  35         struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
  36
  37         kfree(cookie->data);
  38         kfree(cookie);
  39 }
  40
  41 static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
  42                                   struct tc_cookie *new_cookie)
  43 {
  44         struct tc_cookie *old;
  45
  46         old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
  47         if (old)
  48                 call_rcu(&old->rcu, tcf_free_cookie_rcu);
  49 }
  50
  51 int tcf_action_check_ctrlact(int action, struct tcf_proto *tp,
  52                              struct tcf_chain **newchain,
  53                              struct netlink_ext_ack *extack)
  54 {
  55         int opcode = TC_ACT_EXT_OPCODE(action), ret = -EINVAL;
  56         u32 chain_index;
  57
  58         if (!opcode)
  59                 ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0;
  60         else if (opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC)
  61                 ret = 0;
  62         if (ret) {
  63                 NL_SET_ERR_MSG(extack, "invalid control action");
  64                 goto end;
  65         }
  66
  67         if (TC_ACT_EXT_CMP(action, TC_ACT_GOTO_CHAIN)) {
  68                 chain_index = action & TC_ACT_EXT_VAL_MASK;
  69                 if (!tp || !newchain) {
  70                         ret = -EINVAL;
  71                         NL_SET_ERR_MSG(extack,
  72                                        "can't goto NULL proto/chain");
  73                         goto end;
  74                 }
  75                 *newchain = tcf_chain_get_by_act(tp->chain->block, chain_index);
  76                 if (!*newchain) {
  77                         ret = -ENOMEM;
  78                         NL_SET_ERR_MSG(extack,
  79                                        "can't allocate goto_chain");
  80                 }
  81         }
  82 end:
  83         return ret;
  84 }
  85 EXPORT_SYMBOL(tcf_action_check_ctrlact);
  86
  87 struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action,
  88                                          struct tcf_chain *goto_chain)
  89 {
  90         a->tcfa_action = action;
  91         rcu_swap_protected(a->goto_chain, goto_chain, 1);
  92         return goto_chain;
  93 }
  94 EXPORT_SYMBOL(tcf_action_set_ctrlact);
  95
  96 /* XXX: For standalone actions, we don't need a RCU grace period either, because
  97  * actions are always connected to filters and filters are already destroyed in
  98  * RCU callbacks, so after a RCU grace period actions are already disconnected
  99  * from filters. Readers later can not find us.
 100  */
 101 static void free_tcf(struct tc_action *p)
 102 {
 103         struct tcf_chain *chain = rcu_dereference_protected(p->goto_chain, 1);
 104
 105         free_percpu(p->cpu_bstats);
 106         free_percpu(p->cpu_bstats_hw);
 107         free_percpu(p->cpu_qstats);
 108
 109         tcf_set_action_cookie(&p->act_cookie, NULL);
 110         if (chain)
 111                 tcf_chain_put_by_act(chain);
 112
 113         kfree(p);
 114 }
 115
 116 static void tcf_action_cleanup(struct tc_action *p)
 117 {
 118         if (p->ops->cleanup)
 119                 p->ops->cleanup(p);
 120
 121         gen_kill_estimator(&p->tcfa_rate_est);
 122         free_tcf(p);
 123 }
 124
 125 static int __tcf_action_put(struct tc_action *p, bool bind)
 126 {
 127         struct tcf_idrinfo *idrinfo = p->idrinfo;
 128
 129         if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
 130                 if (bind)
 131                         atomic_dec(&p->tcfa_bindcnt);
 132                 idr_remove(&idrinfo->action_idr, p->tcfa_index);
 133                 mutex_unlock(&idrinfo->lock);
 134
 135                 tcf_action_cleanup(p);
 136                 return 1;
 137         }
 138
 139         if (bind)
 140                 atomic_dec(&p->tcfa_bindcnt);
 141
 142         return 0;
 143 }
 144
 145 int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
 146 {
 147         int ret = 0;
 148
 149         /* Release with strict==1 and bind==0 is only called through act API
 150          * interface (classifiers always bind). Only case when action with
 151          * positive reference count and zero bind count can exist is when it was
 152          * also created with act API (unbinding last classifier will destroy the
 153          * action if it was created by classifier). So only case when bind count
 154          * can be changed after initial check is when unbound action is
 155          * destroyed by act API while classifier binds to action with same id
 156          * concurrently. This result either creation of new action(same behavior
 157          * as before), or reusing existing action if concurrent process
 158          * increments reference count before action is deleted. Both scenarios
 159          * are acceptable.
 160          */
 161         if (p) {
 162                 if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
 163                         return -EPERM;
 164
 165                 if (__tcf_action_put(p, bind))
 166                         ret = ACT_P_DELETED;
 167         }
 168
 169         return ret;
 170 }
 171 EXPORT_SYMBOL(__tcf_idr_release);
 172
 173 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
 174 {
 175         struct tc_cookie *act_cookie;
 176         u32 cookie_len = 0;
 177
 178         rcu_read_lock();
 179         act_cookie = rcu_dereference(act->act_cookie);
 180
 181         if (act_cookie)
 182                 cookie_len = nla_total_size(act_cookie->len);
 183         rcu_read_unlock();
 184
 185         return  nla_total_size(0) /* action number nested */
 186                 + nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
 187                 + cookie_len /* TCA_ACT_COOKIE */
 188                 + nla_total_size(0) /* TCA_ACT_STATS nested */
 189                 /* TCA_STATS_BASIC */
 190                 + nla_total_size_64bit(sizeof(struct gnet_stats_basic))
 191                 /* TCA_STATS_QUEUE */
 192                 + nla_total_size_64bit(sizeof(struct gnet_stats_queue))
 193                 + nla_total_size(0) /* TCA_OPTIONS nested */
 194                 + nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
 195 }
 196
 197 static size_t tcf_action_full_attrs_size(size_t sz)
 198 {
 199         return NLMSG_HDRLEN                     /* struct nlmsghdr */
 200                 + sizeof(struct tcamsg)
 201                 + nla_total_size(0)             /* TCA_ACT_TAB nested */
 202                 + sz;
 203 }
 204
 205 static size_t tcf_action_fill_size(const struct tc_action *act)
 206 {
 207         size_t sz = tcf_action_shared_attrs_size(act);
 208
 209         if (act->ops->get_fill_size)
 210                 return act->ops->get_fill_size(act) + sz;
 211         return sz;
 212 }
 213
 214 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 215                            struct netlink_callback *cb)
 216 {
 217         int err = 0, index = -1, s_i = 0, n_i = 0;
 218         u32 act_flags = cb->args[2];
 219         unsigned long jiffy_since = cb->args[3];
 220         struct nlattr *nest;
 221         struct idr *idr = &idrinfo->action_idr;
 222         struct tc_action *p;
 223         unsigned long id = 1;
 224         unsigned long tmp;
 225
 226         mutex_lock(&idrinfo->lock);
 227
 228         s_i = cb->args[0];
 229
 230         idr_for_each_entry_ul(idr, p, tmp, id) {
 231                 index++;
 232                 if (index < s_i)
 233                         continue;
 234
 235                 if (jiffy_since &&
 236                     time_after(jiffy_since,
 237                                (unsigned long)p->tcfa_tm.lastuse))
 238                         continue;
 239
 240                 nest = nla_nest_start_noflag(skb, n_i);
 241                 if (!nest) {
 242                         index--;
 243                         goto nla_put_failure;
 244                 }
 245                 err = tcf_action_dump_1(skb, p, 0, 0);
 246                 if (err < 0) {
 247                         index--;
 248                         nlmsg_trim(skb, nest);
 249                         goto done;
 250                 }
 251                 nla_nest_end(skb, nest);
 252                 n_i++;
 253                 if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
 254                     n_i >= TCA_ACT_MAX_PRIO)
 255                         goto done;
 256         }
 257 done:
 258         if (index >= 0)
 259                 cb->args[0] = index + 1;
 260
 261         mutex_unlock(&idrinfo->lock);
 262         if (n_i) {
 263                 if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
 264                         cb->args[1] = n_i;
 265         }
 266         return n_i;
 267
 268 nla_put_failure:
 269         nla_nest_cancel(skb, nest);
 270         goto done;
 271 }
 272
 273 static int tcf_idr_release_unsafe(struct tc_action *p)
 274 {
 275         if (atomic_read(&p->tcfa_bindcnt) > 0)
 276                 return -EPERM;
 277
 278         if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 279                 idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
 280                 tcf_action_cleanup(p);
 281                 return ACT_P_DELETED;
 282         }
 283
 284         return 0;
 285 }
 286
 287 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
 288                           const struct tc_action_ops *ops)
 289 {
 290         struct nlattr *nest;
 291         int n_i = 0;
 292         int ret = -EINVAL;
 293         struct idr *idr = &idrinfo->action_idr;
 294         struct tc_action *p;
 295         unsigned long id = 1;
 296         unsigned long tmp;
 297
 298         nest = nla_nest_start_noflag(skb, 0);
 299         if (nest == NULL)
 300                 goto nla_put_failure;
 301         if (nla_put_string(skb, TCA_KIND, ops->kind))
 302                 goto nla_put_failure;
 303
 304         mutex_lock(&idrinfo->lock);
 305         idr_for_each_entry_ul(idr, p, tmp, id) {
 306                 ret = tcf_idr_release_unsafe(p);
 307                 if (ret == ACT_P_DELETED) {
 308                         module_put(ops->owner);
 309                         n_i++;
 310                 } else if (ret < 0) {
 311                         mutex_unlock(&idrinfo->lock);
 312                         goto nla_put_failure;
 313                 }
 314         }
 315         mutex_unlock(&idrinfo->lock);
 316
 317         if (nla_put_u32(skb, TCA_FCNT, n_i))
 318                 goto nla_put_failure;
 319         nla_nest_end(skb, nest);
 320
 321         return n_i;
 322 nla_put_failure:
 323         nla_nest_cancel(skb, nest);
 324         return ret;
 325 }
 326
 327 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 328                        struct netlink_callback *cb, int type,
 329                        const struct tc_action_ops *ops,
 330                        struct netlink_ext_ack *extack)
 331 {
 332         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 333
 334         if (type == RTM_DELACTION) {
 335                 return tcf_del_walker(idrinfo, skb, ops);
 336         } else if (type == RTM_GETACTION) {
 337                 return tcf_dump_walker(idrinfo, skb, cb);
 338         } else {
 339                 WARN(1, "tcf_generic_walker: unknown command %d\n", type);
 340                 NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
 341                 return -EINVAL;
 342         }
 343 }
 344 EXPORT_SYMBOL(tcf_generic_walker);
 345
 346 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 347 {
 348         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 349         struct tc_action *p;
 350
 351         mutex_lock(&idrinfo->lock);
 352         p = idr_find(&idrinfo->action_idr, index);
 353         if (IS_ERR(p))
 354                 p = NULL;
 355         else if (p)
 356                 refcount_inc(&p->tcfa_refcnt);
 357         mutex_unlock(&idrinfo->lock);
 358
 359         if (p) {
 360                 *a = p;
 361                 return true;
 362         }
 363         return false;
 364 }
 365 EXPORT_SYMBOL(tcf_idr_search);
 366
 367 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
 368 {
 369         struct tc_action *p;
 370         int ret = 0;
 371
 372         mutex_lock(&idrinfo->lock);
 373         p = idr_find(&idrinfo->action_idr, index);
 374         if (!p) {
 375                 mutex_unlock(&idrinfo->lock);
 376                 return -ENOENT;
 377         }
 378
 379         if (!atomic_read(&p->tcfa_bindcnt)) {
 380                 if (refcount_dec_and_test(&p->tcfa_refcnt)) {
 381                         struct module *owner = p->ops->owner;
 382
 383                         WARN_ON(p != idr_remove(&idrinfo->action_idr,
 384                                                 p->tcfa_index));
 385                         mutex_unlock(&idrinfo->lock);
 386
 387                         tcf_action_cleanup(p);
 388                         module_put(owner);
 389                         return 0;
 390                 }
 391                 ret = 0;
 392         } else {
 393                 ret = -EPERM;
 394         }
 395
 396         mutex_unlock(&idrinfo->lock);
 397         return ret;
 398 }
 399
 400 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 401                    struct tc_action **a, const struct tc_action_ops *ops,
 402                    int bind, bool cpustats)
 403 {
 404         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 405         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 406         int err = -ENOMEM;
 407
 408         if (unlikely(!p))
 409                 return -ENOMEM;
 410         refcount_set(&p->tcfa_refcnt, 1);
 411         if (bind)
 412                 atomic_set(&p->tcfa_bindcnt, 1);
 413
 414         if (cpustats) {
 415                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 416                 if (!p->cpu_bstats)
 417                         goto err1;
 418                 p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 419                 if (!p->cpu_bstats_hw)
 420                         goto err2;
 421                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 422                 if (!p->cpu_qstats)
 423                         goto err3;
 424         }
 425         spin_lock_init(&p->tcfa_lock);
 426         p->tcfa_index = index;
 427         p->tcfa_tm.install = jiffies;
 428         p->tcfa_tm.lastuse = jiffies;
 429         p->tcfa_tm.firstuse = 0;
 430         if (est) {
 431                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 432                                         &p->tcfa_rate_est,
 433                                         &p->tcfa_lock, NULL, est);
 434                 if (err)
 435                         goto err4;
 436         }
 437
 438         p->idrinfo = idrinfo;
 439         p->ops = ops;
 440         *a = p;
 441         return 0;
 442 err4:
 443         free_percpu(p->cpu_qstats);
 444 err3:
 445         free_percpu(p->cpu_bstats_hw);
 446 err2:
 447         free_percpu(p->cpu_bstats);
 448 err1:
 449         kfree(p);
 450         return err;
 451 }
 452 EXPORT_SYMBOL(tcf_idr_create);
 453
 454 void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
 455 {
 456         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 457
 458         mutex_lock(&idrinfo->lock);
 459         /* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 460         WARN_ON(!IS_ERR(idr_replace(&idrinfo->action_idr, a, a->tcfa_index)));
 461         mutex_unlock(&idrinfo->lock);
 462 }
 463 EXPORT_SYMBOL(tcf_idr_insert);
 464
 465 /* Cleanup idr index that was allocated but not initialized. */
 466
 467 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
 468 {
 469         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 470
 471         mutex_lock(&idrinfo->lock);
 472         /* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
 473         WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
 474         mutex_unlock(&idrinfo->lock);
 475 }
 476 EXPORT_SYMBOL(tcf_idr_cleanup);
 477
 478 /* Check if action with specified index exists. If actions is found, increments
 479  * its reference and bind counters, and return 1. Otherwise insert temporary
 480  * error pointer (to prevent concurrent users from inserting actions with same
 481  * index) and return 0.
 482  */
 483
 484 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
 485                         struct tc_action **a, int bind)
 486 {
 487         struct tcf_idrinfo *idrinfo = tn->idrinfo;
 488         struct tc_action *p;
 489         int ret;
 490
 491 again:
 492         mutex_lock(&idrinfo->lock);
 493         if (*index) {
 494                 p = idr_find(&idrinfo->action_idr, *index);
 495                 if (IS_ERR(p)) {
 496                         /* This means that another process allocated
 497                          * index but did not assign the pointer yet.
 498                          */
 499                         mutex_unlock(&idrinfo->lock);
 500                         goto again;
 501                 }
 502
 503                 if (p) {
 504                         refcount_inc(&p->tcfa_refcnt);
 505                         if (bind)
 506                                 atomic_inc(&p->tcfa_bindcnt);
 507                         *a = p;
 508                         ret = 1;
 509                 } else {
 510                         *a = NULL;
 511                         ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 512                                             *index, GFP_KERNEL);
 513                         if (!ret)
 514                                 idr_replace(&idrinfo->action_idr,
 515                                             ERR_PTR(-EBUSY), *index);
 516                 }
 517         } else {
 518                 *index = 1;
 519                 *a = NULL;
 520                 ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
 521                                     UINT_MAX, GFP_KERNEL);
 522                 if (!ret)
 523                         idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
 524                                     *index);
 525         }
 526         mutex_unlock(&idrinfo->lock);
 527         return ret;
 528 }
 529 EXPORT_SYMBOL(tcf_idr_check_alloc);
 530
 531 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
 532                          struct tcf_idrinfo *idrinfo)
 533 {
 534         struct idr *idr = &idrinfo->action_idr;
 535         struct tc_action *p;
 536         int ret;
 537         unsigned long id = 1;
 538         unsigned long tmp;
 539
 540         idr_for_each_entry_ul(idr, p, tmp, id) {
 541                 ret = __tcf_idr_release(p, false, true);
 542                 if (ret == ACT_P_DELETED)
 543                         module_put(ops->owner);
 544                 else if (ret < 0)
 545                         return;
 546         }
 547         idr_destroy(&idrinfo->action_idr);
 548 }
 549 EXPORT_SYMBOL(tcf_idrinfo_destroy);
 550
 551 static LIST_HEAD(act_base);
 552 static DEFINE_RWLOCK(act_mod_lock);
 553
 554 int tcf_register_action(struct tc_action_ops *act,
 555                         struct pernet_operations *ops)
 556 {
 557         struct tc_action_ops *a;
 558         int ret;
 559
 560         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 561                 return -EINVAL;
 562
 563         /* We have to register pernet ops before making the action ops visible,
 564          * otherwise tcf_action_init_1() could get a partially initialized
 565          * netns.
 566          */
 567         ret = register_pernet_subsys(ops);
 568         if (ret)
 569                 return ret;
 570
 571         write_lock(&act_mod_lock);
 572         list_for_each_entry(a, &act_base, head) {
 573                 if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
 574                         write_unlock(&act_mod_lock);
 575                         unregister_pernet_subsys(ops);
 576                         return -EEXIST;
 577                 }
 578         }
 579         list_add_tail(&act->head, &act_base);
 580         write_unlock(&act_mod_lock);
 581
 582         return 0;
 583 }
 584 EXPORT_SYMBOL(tcf_register_action);
 585
 586 int tcf_unregister_action(struct tc_action_ops *act,
 587                           struct pernet_operations *ops)
 588 {
 589         struct tc_action_ops *a;
 590         int err = -ENOENT;
 591
 592         write_lock(&act_mod_lock);
 593         list_for_each_entry(a, &act_base, head) {
 594                 if (a == act) {
 595                         list_del(&act->head);
 596                         err = 0;
 597                         break;
 598                 }
 599         }
 600         write_unlock(&act_mod_lock);
 601         if (!err)
 602                 unregister_pernet_subsys(ops);
 603         return err;
 604 }
 605 EXPORT_SYMBOL(tcf_unregister_action);
 606
 607 /* lookup by name */
 608 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 609 {
 610         struct tc_action_ops *a, *res = NULL;
 611
 612         if (kind) {
 613                 read_lock(&act_mod_lock);
 614                 list_for_each_entry(a, &act_base, head) {
 615                         if (strcmp(kind, a->kind) == 0) {
 616                                 if (try_module_get(a->owner))
 617                                         res = a;
 618                                 break;
 619                         }
 620                 }
 621                 read_unlock(&act_mod_lock);
 622         }
 623         return res;
 624 }
 625
 626 /* lookup by nlattr */
 627 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 628 {
 629         struct tc_action_ops *a, *res = NULL;
 630
 631         if (kind) {
 632                 read_lock(&act_mod_lock);
 633                 list_for_each_entry(a, &act_base, head) {
 634                         if (nla_strcmp(kind, a->kind) == 0) {
 635                                 if (try_module_get(a->owner))
 636                                         res = a;
 637                                 break;
 638                         }
 639                 }
 640                 read_unlock(&act_mod_lock);
 641         }
 642         return res;
 643 }
 644
 645 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
 646 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 647 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 648                     int nr_actions, struct tcf_result *res)
 649 {
 650         u32 jmp_prgcnt = 0;
 651         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 652         int i;
 653         int ret = TC_ACT_OK;
 654
 655         if (skb_skip_tc_classify(skb))
 656                 return TC_ACT_OK;
 657
 658 restart_act_graph:
 659         for (i = 0; i < nr_actions; i++) {
 660                 const struct tc_action *a = actions[i];
 661
 662                 if (jmp_prgcnt > 0) {
 663                         jmp_prgcnt -= 1;
 664                         continue;
 665                 }
 666 repeat:
 667                 ret = a->ops->act(skb, a, res);
 668                 if (ret == TC_ACT_REPEAT)
 669                         goto repeat;    /* we need a ttl - JHS */
 670
 671                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 672                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 673                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 674                                 /* faulty opcode, stop pipeline */
 675                                 return TC_ACT_OK;
 676                         } else {
 677                                 jmp_ttl -= 1;
 678                                 if (jmp_ttl > 0)
 679                                         goto restart_act_graph;
 680                                 else /* faulty graph, stop pipeline */
 681                                         return TC_ACT_OK;
 682                         }
 683                 } else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 684                         if (unlikely(!rcu_access_pointer(a->goto_chain))) {
 685                                 net_warn_ratelimited("can't go to NULL chain!\n");
 686                                 return TC_ACT_SHOT;
 687                         }
 688                         tcf_action_goto_chain_exec(a, res);
 689                 }
 690
 691                 if (ret != TC_ACT_PIPE)
 692                         break;
 693         }
 694
 695         return ret;
 696 }
 697 EXPORT_SYMBOL(tcf_action_exec);
 698
 699 int tcf_action_destroy(struct tc_action *actions[], int bind)
 700 {
 701         const struct tc_action_ops *ops;
 702         struct tc_action *a;
 703         int ret = 0, i;
 704
 705         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 706                 a = actions[i];
 707                 actions[i] = NULL;
 708                 ops = a->ops;
 709                 ret = __tcf_idr_release(a, bind, true);
 710                 if (ret == ACT_P_DELETED)
 711                         module_put(ops->owner);
 712                 else if (ret < 0)
 713                         return ret;
 714         }
 715         return ret;
 716 }
 717
 718 static int tcf_action_destroy_1(struct tc_action *a, int bind)
 719 {
 720         struct tc_action *actions[] = { a, NULL };
 721
 722         return tcf_action_destroy(actions, bind);
 723 }
 724
 725 static int tcf_action_put(struct tc_action *p)
 726 {
 727         return __tcf_action_put(p, false);
 728 }
 729
 730 /* Put all actions in this array, skip those NULL's. */
 731 static void tcf_action_put_many(struct tc_action *actions[])
 732 {
 733         int i;
 734
 735         for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
 736                 struct tc_action *a = actions[i];
 737                 const struct tc_action_ops *ops;
 738
 739                 if (!a)
 740                         continue;
 741                 ops = a->ops;
 742                 if (tcf_action_put(a))
 743                         module_put(ops->owner);
 744         }
 745 }
 746
 747 int
 748 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 749 {
 750         return a->ops->dump(skb, a, bind, ref);
 751 }
 752
 753 int
 754 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 755 {
 756         int err = -EINVAL;
 757         unsigned char *b = skb_tail_pointer(skb);
 758         struct nlattr *nest;
 759         struct tc_cookie *cookie;
 760
 761         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 762                 goto nla_put_failure;
 763         if (tcf_action_copy_stats(skb, a, 0))
 764                 goto nla_put_failure;
 765
 766         rcu_read_lock();
 767         cookie = rcu_dereference(a->act_cookie);
 768         if (cookie) {
 769                 if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
 770                         rcu_read_unlock();
 771                         goto nla_put_failure;
 772                 }
 773         }
 774         rcu_read_unlock();
 775
 776         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 777         if (nest == NULL)
 778                 goto nla_put_failure;
 779         err = tcf_action_dump_old(skb, a, bind, ref);
 780         if (err > 0) {
 781                 nla_nest_end(skb, nest);
 782                 return err;
 783         }
 784
 785 nla_put_failure:
 786         nlmsg_trim(skb, b);
 787         return -1;
 788 }
 789 EXPORT_SYMBOL(tcf_action_dump_1);
 790
 791 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
 792                     int bind, int ref)
 793 {
 794         struct tc_action *a;
 795         int err = -EINVAL, i;
 796         struct nlattr *nest;
 797
 798         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
 799                 a = actions[i];
 800                 nest = nla_nest_start_noflag(skb, i + 1);
 801                 if (nest == NULL)
 802                         goto nla_put_failure;
 803                 err = tcf_action_dump_1(skb, a, bind, ref);
 804                 if (err < 0)
 805                         goto errout;
 806                 nla_nest_end(skb, nest);
 807         }
 808
 809         return 0;
 810
 811 nla_put_failure:
 812         err = -EINVAL;
 813 errout:
 814         nla_nest_cancel(skb, nest);
 815         return err;
 816 }
 817
 818 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 819 {
 820         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 821         if (!c)
 822                 return NULL;
 823
 824         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 825         if (!c->data) {
 826                 kfree(c);
 827                 return NULL;
 828         }
 829         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 830
 831         return c;
 832 }
 833
 834 static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
 835         [TCA_ACT_KIND]          = { .type = NLA_STRING },
 836         [TCA_ACT_INDEX]         = { .type = NLA_U32 },
 837         [TCA_ACT_COOKIE]        = { .type = NLA_BINARY,
 838                                     .len = TC_COOKIE_MAX_SIZE },
 839         [TCA_ACT_OPTIONS]       = { .type = NLA_NESTED },
 840 };
 841
 842 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 843                                     struct nlattr *nla, struct nlattr *est,
 844                                     char *name, int ovr, int bind,
 845                                     bool rtnl_held,
 846                                     struct netlink_ext_ack *extack)
 847 {
 848         struct tc_action *a;
 849         struct tc_action_ops *a_o;
 850         struct tc_cookie *cookie = NULL;
 851         char act_name[IFNAMSIZ];
 852         struct nlattr *tb[TCA_ACT_MAX + 1];
 853         struct nlattr *kind;
 854         int err;
 855
 856         if (name == NULL) {
 857                 err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
 858                                                   tcf_action_policy, extack);
 859                 if (err < 0)
 860                         goto err_out;
 861                 err = -EINVAL;
 862                 kind = tb[TCA_ACT_KIND];
 863                 if (!kind) {
 864                         NL_SET_ERR_MSG(extack, "TC action kind must be specified");
 865                         goto err_out;
 866                 }
 867                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
 868                         NL_SET_ERR_MSG(extack, "TC action name too long");
 869                         goto err_out;
 870                 }
 871                 if (tb[TCA_ACT_COOKIE]) {
 872                         cookie = nla_memdup_cookie(tb);
 873                         if (!cookie) {
 874                                 NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
 875                                 err = -ENOMEM;
 876                                 goto err_out;
 877                         }
 878                 }
 879         } else {
 880                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
 881                         NL_SET_ERR_MSG(extack, "TC action name too long");
 882                         err = -EINVAL;
 883                         goto err_out;
 884                 }
 885         }
 886
 887         a_o = tc_lookup_action_n(act_name);
 888         if (a_o == NULL) {
 889 #ifdef CONFIG_MODULES
 890                 if (rtnl_held)
 891                         rtnl_unlock();
 892                 request_module("act_%s", act_name);
 893                 if (rtnl_held)
 894                         rtnl_lock();
 895
 896                 a_o = tc_lookup_action_n(act_name);
 897
 898                 /* We dropped the RTNL semaphore in order to
 899                  * perform the module load.  So, even if we
 900                  * succeeded in loading the module we have to
 901                  * tell the caller to replay the request.  We
 902                  * indicate this using -EAGAIN.
 903                  */
 904                 if (a_o != NULL) {
 905                         err = -EAGAIN;
 906                         goto err_mod;
 907                 }
 908 #endif
 909                 NL_SET_ERR_MSG(extack, "Failed to load TC action module");
 910                 err = -ENOENT;
 911                 goto err_out;
 912         }
 913
 914         /* backward compatibility for policer */
 915         if (name == NULL)
 916                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
 917                                 rtnl_held, tp, extack);
 918         else
 919                 err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
 920                                 tp, extack);
 921         if (err < 0)
 922                 goto err_mod;
 923
 924         if (!name && tb[TCA_ACT_COOKIE])
 925                 tcf_set_action_cookie(&a->act_cookie, cookie);
 926
 927         /* module count goes up only when brand new policy is created
 928          * if it exists and is only bound to in a_o->init() then
 929          * ACT_P_CREATED is not returned (a zero is).
 930          */
 931         if (err != ACT_P_CREATED)
 932                 module_put(a_o->owner);
 933
 934         if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN) &&
 935             !rcu_access_pointer(a->goto_chain)) {
 936                 tcf_action_destroy_1(a, bind);
 937                 NL_SET_ERR_MSG(extack, "can't use goto chain with NULL chain");
 938                 return ERR_PTR(-EINVAL);
 939         }
 940
 941         return a;
 942
 943 err_mod:
 944         module_put(a_o->owner);
 945 err_out:
 946         if (cookie) {
 947                 kfree(cookie->data);
 948                 kfree(cookie);
 949         }
 950         return ERR_PTR(err);
 951 }
 952
 953 /* Returns numbers of initialized actions or negative error. */
 954
 955 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 956                     struct nlattr *est, char *name, int ovr, int bind,
 957                     struct tc_action *actions[], size_t *attr_size,
 958                     bool rtnl_held, struct netlink_ext_ack *extack)
 959 {
 960         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 961         struct tc_action *act;
 962         size_t sz = 0;
 963         int err;
 964         int i;
 965
 966         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
 967                                           extack);
 968         if (err < 0)
 969                 return err;
 970
 971         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 972                 act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
 973                                         rtnl_held, extack);
 974                 if (IS_ERR(act)) {
 975                         err = PTR_ERR(act);
 976                         goto err;
 977                 }
 978                 act->order = i;
 979                 sz += tcf_action_fill_size(act);
 980                 /* Start from index 0 */
 981                 actions[i - 1] = act;
 982         }
 983
 984         *attr_size = tcf_action_full_attrs_size(sz);
 985         return i - 1;
 986
 987 err:
 988         tcf_action_destroy(actions, bind);
 989         return err;
 990 }
 991
 992 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
 993                           int compat_mode)
 994 {
 995         int err = 0;
 996         struct gnet_dump d;
 997
 998         if (p == NULL)
 999                 goto errout;
1000
1001         /* compat_mode being true specifies a call that is supposed
1002          * to add additional backward compatibility statistic TLVs.
1003          */
1004         if (compat_mode) {
1005                 if (p->type == TCA_OLD_COMPAT)
1006                         err = gnet_stats_start_copy_compat(skb, 0,
1007                                                            TCA_STATS,
1008                                                            TCA_XSTATS,
1009                                                            &p->tcfa_lock, &d,
1010                                                            TCA_PAD);
1011                 else
1012                         return 0;
1013         } else
1014                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1015                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
1016
1017         if (err < 0)
1018                 goto errout;
1019
1020         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
1021             gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
1022                                      &p->tcfa_bstats_hw) < 0 ||
1023             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1024             gnet_stats_copy_queue(&d, p->cpu_qstats,
1025                                   &p->tcfa_qstats,
1026                                   p->tcfa_qstats.qlen) < 0)
1027                 goto errout;
1028
1029         if (gnet_stats_finish_copy(&d) < 0)
1030                 goto errout;
1031
1032         return 0;
1033
1034 errout:
1035         return -1;
1036 }
1037
1038 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1039                         u32 portid, u32 seq, u16 flags, int event, int bind,
1040                         int ref)
1041 {
1042         struct tcamsg *t;
1043         struct nlmsghdr *nlh;
1044         unsigned char *b = skb_tail_pointer(skb);
1045         struct nlattr *nest;
1046
1047         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1048         if (!nlh)
1049                 goto out_nlmsg_trim;
1050         t = nlmsg_data(nlh);
1051         t->tca_family = AF_UNSPEC;
1052         t->tca__pad1 = 0;
1053         t->tca__pad2 = 0;
1054
1055         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1056         if (!nest)
1057                 goto out_nlmsg_trim;
1058
1059         if (tcf_action_dump(skb, actions, bind, ref) < 0)
1060                 goto out_nlmsg_trim;
1061
1062         nla_nest_end(skb, nest);
1063
1064         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1065         return skb->len;
1066
1067 out_nlmsg_trim:
1068         nlmsg_trim(skb, b);
1069         return -1;
1070 }
1071
1072 static int
1073 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1074                struct tc_action *actions[], int event,
1075                struct netlink_ext_ack *extack)
1076 {
1077         struct sk_buff *skb;
1078
1079         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1080         if (!skb)
1081                 return -ENOBUFS;
1082         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1083                          0, 1) <= 0) {
1084                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1085                 kfree_skb(skb);
1086                 return -EINVAL;
1087         }
1088
1089         return rtnl_unicast(skb, net, portid);
1090 }
1091
1092 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1093                                           struct nlmsghdr *n, u32 portid,
1094                                           struct netlink_ext_ack *extack)
1095 {
1096         struct nlattr *tb[TCA_ACT_MAX + 1];
1097         const struct tc_action_ops *ops;
1098         struct tc_action *a;
1099         int index;
1100         int err;
1101
1102         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1103                                           tcf_action_policy, extack);
1104         if (err < 0)
1105                 goto err_out;
1106
1107         err = -EINVAL;
1108         if (tb[TCA_ACT_INDEX] == NULL ||
1109             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1110                 NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1111                 goto err_out;
1112         }
1113         index = nla_get_u32(tb[TCA_ACT_INDEX]);
1114
1115         err = -EINVAL;
1116         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1117         if (!ops) { /* could happen in batch of actions */
1118                 NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1119                 goto err_out;
1120         }
1121         err = -ENOENT;
1122         if (ops->lookup(net, &a, index) == 0) {
1123                 NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1124                 goto err_mod;
1125         }
1126
1127         module_put(ops->owner);
1128         return a;
1129
1130 err_mod:
1131         module_put(ops->owner);
1132 err_out:
1133         return ERR_PTR(err);
1134 }
1135
1136 static int tca_action_flush(struct net *net, struct nlattr *nla,
1137                             struct nlmsghdr *n, u32 portid,
1138                             struct netlink_ext_ack *extack)
1139 {
1140         struct sk_buff *skb;
1141         unsigned char *b;
1142         struct nlmsghdr *nlh;
1143         struct tcamsg *t;
1144         struct netlink_callback dcb;
1145         struct nlattr *nest;
1146         struct nlattr *tb[TCA_ACT_MAX + 1];
1147         const struct tc_action_ops *ops;
1148         struct nlattr *kind;
1149         int err = -ENOMEM;
1150
1151         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1152         if (!skb)
1153                 return err;
1154
1155         b = skb_tail_pointer(skb);
1156
1157         err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1158                                           tcf_action_policy, extack);
1159         if (err < 0)
1160                 goto err_out;
1161
1162         err = -EINVAL;
1163         kind = tb[TCA_ACT_KIND];
1164         ops = tc_lookup_action(kind);
1165         if (!ops) { /*some idjot trying to flush unknown action */
1166                 NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1167                 goto err_out;
1168         }
1169
1170         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1171                         sizeof(*t), 0);
1172         if (!nlh) {
1173                 NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1174                 goto out_module_put;
1175         }
1176         t = nlmsg_data(nlh);
1177         t->tca_family = AF_UNSPEC;
1178         t->tca__pad1 = 0;
1179         t->tca__pad2 = 0;
1180
1181         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1182         if (!nest) {
1183                 NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1184                 goto out_module_put;
1185         }
1186
1187         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1188         if (err <= 0) {
1189                 nla_nest_cancel(skb, nest);
1190                 goto out_module_put;
1191         }
1192
1193         nla_nest_end(skb, nest);
1194
1195         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1196         nlh->nlmsg_flags |= NLM_F_ROOT;
1197         module_put(ops->owner);
1198         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1199                              n->nlmsg_flags & NLM_F_ECHO);
1200         if (err > 0)
1201                 return 0;
1202         if (err < 0)
1203                 NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1204
1205         return err;
1206
1207 out_module_put:
1208         module_put(ops->owner);
1209 err_out:
1210         kfree_skb(skb);
1211         return err;
1212 }
1213
1214 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1215 {
1216         int i;
1217
1218         for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1219                 struct tc_action *a = actions[i];
1220                 const struct tc_action_ops *ops = a->ops;
1221                 /* Actions can be deleted concurrently so we must save their
1222                  * type and id to search again after reference is released.
1223                  */
1224                 struct tcf_idrinfo *idrinfo = a->idrinfo;
1225                 u32 act_index = a->tcfa_index;
1226
1227                 actions[i] = NULL;
1228                 if (tcf_action_put(a)) {
1229                         /* last reference, action was deleted concurrently */
1230                         module_put(ops->owner);
1231                 } else  {
1232                         int ret;
1233
1234                         /* now do the delete */
1235                         ret = tcf_idr_delete_index(idrinfo, act_index);
1236                         if (ret < 0)
1237                                 return ret;
1238                 }
1239         }
1240         return 0;
1241 }
1242
1243 static int
1244 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1245                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1246 {
1247         int ret;
1248         struct sk_buff *skb;
1249
1250         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1251                         GFP_KERNEL);
1252         if (!skb)
1253                 return -ENOBUFS;
1254
1255         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1256                          0, 2) <= 0) {
1257                 NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1258                 kfree_skb(skb);
1259                 return -EINVAL;
1260         }
1261
1262         /* now do the delete */
1263         ret = tcf_action_delete(net, actions);
1264         if (ret < 0) {
1265                 NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1266                 kfree_skb(skb);
1267                 return ret;
1268         }
1269
1270         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1271                              n->nlmsg_flags & NLM_F_ECHO);
1272         if (ret > 0)
1273                 return 0;
1274         return ret;
1275 }
1276
1277 static int
1278 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1279               u32 portid, int event, struct netlink_ext_ack *extack)
1280 {
1281         int i, ret;
1282         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1283         struct tc_action *act;
1284         size_t attr_size = 0;
1285         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1286
1287         ret = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1288                                           extack);
1289         if (ret < 0)
1290                 return ret;
1291
1292         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1293                 if (tb[1])
1294                         return tca_action_flush(net, tb[1], n, portid, extack);
1295
1296                 NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1297                 return -EINVAL;
1298         }
1299
1300         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1301                 act = tcf_action_get_1(net, tb[i], n, portid, extack);
1302                 if (IS_ERR(act)) {
1303                         ret = PTR_ERR(act);
1304                         goto err;
1305                 }
1306                 attr_size += tcf_action_fill_size(act);
1307                 actions[i - 1] = act;
1308         }
1309
1310         attr_size = tcf_action_full_attrs_size(attr_size);
1311
1312         if (event == RTM_GETACTION)
1313                 ret = tcf_get_notify(net, portid, n, actions, event, extack);
1314         else { /* delete */
1315                 ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1316                 if (ret)
1317                         goto err;
1318                 return 0;
1319         }
1320 err:
1321         tcf_action_put_many(actions);
1322         return ret;
1323 }
1324
1325 static int
1326 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1327                u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1328 {
1329         struct sk_buff *skb;
1330         int err = 0;
1331
1332         skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1333                         GFP_KERNEL);
1334         if (!skb)
1335                 return -ENOBUFS;
1336
1337         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1338                          RTM_NEWACTION, 0, 0) <= 0) {
1339                 NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1340                 kfree_skb(skb);
1341                 return -EINVAL;
1342         }
1343
1344         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1345                              n->nlmsg_flags & NLM_F_ECHO);
1346         if (err > 0)
1347                 err = 0;
1348         return err;
1349 }
1350
1351 static int tcf_action_add(struct net *net, struct nlattr *nla,
1352                           struct nlmsghdr *n, u32 portid, int ovr,
1353                           struct netlink_ext_ack *extack)
1354 {
1355         size_t attr_size = 0;
1356         int loop, ret;
1357         struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1358
1359         for (loop = 0; loop < 10; loop++) {
1360                 ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0,
1361                                       actions, &attr_size, true, extack);
1362                 if (ret != -EAGAIN)
1363                         break;
1364         }
1365
1366         if (ret < 0)
1367                 return ret;
1368         ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1369         if (ovr)
1370                 tcf_action_put_many(actions);
1371
1372         return ret;
1373 }
1374
1375 static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
1376 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1377         [TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
1378                              .validation_data = &tcaa_root_flags_allowed },
1379         [TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1380 };
1381
1382 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1383                          struct netlink_ext_ack *extack)
1384 {
1385         struct net *net = sock_net(skb->sk);
1386         struct nlattr *tca[TCA_ROOT_MAX + 1];
1387         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1388         int ret = 0, ovr = 0;
1389
1390         if ((n->nlmsg_type != RTM_GETACTION) &&
1391             !netlink_capable(skb, CAP_NET_ADMIN))
1392                 return -EPERM;
1393
1394         ret = nlmsg_parse_deprecated(n, sizeof(struct tcamsg), tca,
1395                                      TCA_ROOT_MAX, NULL, extack);
1396         if (ret < 0)
1397                 return ret;
1398
1399         if (tca[TCA_ACT_TAB] == NULL) {
1400                 NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1401                 return -EINVAL;
1402         }
1403
1404         /* n->nlmsg_flags & NLM_F_CREATE */
1405         switch (n->nlmsg_type) {
1406         case RTM_NEWACTION:
1407                 /* we are going to assume all other flags
1408                  * imply create only if it doesn't exist
1409                  * Note that CREATE | EXCL implies that
1410                  * but since we want avoid ambiguity (eg when flags
1411                  * is zero) then just set this
1412                  */
1413                 if (n->nlmsg_flags & NLM_F_REPLACE)
1414                         ovr = 1;
1415                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1416                                      extack);
1417                 break;
1418         case RTM_DELACTION:
1419                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1420                                     portid, RTM_DELACTION, extack);
1421                 break;
1422         case RTM_GETACTION:
1423                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1424                                     portid, RTM_GETACTION, extack);
1425                 break;
1426         default:
1427                 BUG();
1428         }
1429
1430         return ret;
1431 }
1432
1433 static struct nlattr *find_dump_kind(struct nlattr **nla)
1434 {
1435         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1436         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1437         struct nlattr *kind;
1438
1439         tb1 = nla[TCA_ACT_TAB];
1440         if (tb1 == NULL)
1441                 return NULL;
1442
1443         if (nla_parse_deprecated(tb, TCA_ACT_MAX_PRIO, nla_data(tb1), NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1444                 return NULL;
1445
1446         if (tb[1] == NULL)
1447                 return NULL;
1448         if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], tcf_action_policy, NULL) < 0)
1449                 return NULL;
1450         kind = tb2[TCA_ACT_KIND];
1451
1452         return kind;
1453 }
1454
1455 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1456 {
1457         struct net *net = sock_net(skb->sk);
1458         struct nlmsghdr *nlh;
1459         unsigned char *b = skb_tail_pointer(skb);
1460         struct nlattr *nest;
1461         struct tc_action_ops *a_o;
1462         int ret = 0;
1463         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1464         struct nlattr *tb[TCA_ROOT_MAX + 1];
1465         struct nlattr *count_attr = NULL;
1466         unsigned long jiffy_since = 0;
1467         struct nlattr *kind = NULL;
1468         struct nla_bitfield32 bf;
1469         u32 msecs_since = 0;
1470         u32 act_count = 0;
1471
1472         ret = nlmsg_parse_deprecated(cb->nlh, sizeof(struct tcamsg), tb,
1473                                      TCA_ROOT_MAX, tcaa_policy, cb->extack);
1474         if (ret < 0)
1475                 return ret;
1476
1477         kind = find_dump_kind(tb);
1478         if (kind == NULL) {
1479                 pr_info("tc_dump_action: action bad kind\n");
1480                 return 0;
1481         }
1482
1483         a_o = tc_lookup_action(kind);
1484         if (a_o == NULL)
1485                 return 0;
1486
1487         cb->args[2] = 0;
1488         if (tb[TCA_ROOT_FLAGS]) {
1489                 bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1490                 cb->args[2] = bf.value;
1491         }
1492
1493         if (tb[TCA_ROOT_TIME_DELTA]) {
1494                 msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1495         }
1496
1497         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1498                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1499         if (!nlh)
1500                 goto out_module_put;
1501
1502         if (msecs_since)
1503                 jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1504
1505         t = nlmsg_data(nlh);
1506         t->tca_family = AF_UNSPEC;
1507         t->tca__pad1 = 0;
1508         t->tca__pad2 = 0;
1509         cb->args[3] = jiffy_since;
1510         count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1511         if (!count_attr)
1512                 goto out_module_put;
1513
1514         nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1515         if (nest == NULL)
1516                 goto out_module_put;
1517
1518         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1519         if (ret < 0)
1520                 goto out_module_put;
1521
1522         if (ret > 0) {
1523                 nla_nest_end(skb, nest);
1524                 ret = skb->len;
1525                 act_count = cb->args[1];
1526                 memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1527                 cb->args[1] = 0;
1528         } else
1529                 nlmsg_trim(skb, b);
1530
1531         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1532         if (NETLINK_CB(cb->skb).portid && ret)
1533                 nlh->nlmsg_flags |= NLM_F_MULTI;
1534         module_put(a_o->owner);
1535         return skb->len;
1536
1537 out_module_put:
1538         module_put(a_o->owner);
1539         nlmsg_trim(skb, b);
1540         return skb->len;
1541 }
1542
1543 static int __init tc_action_init(void)
1544 {
1545         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1546         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1547         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1548                       0);
1549
1550         return 0;
1551 }
1552
1553 subsys_initcall(tc_action_init);